Scraper

Abstract

This disclosure relates to an automatically controlled scraper for moving particulate material onto a radial or star feeder for distribution thereby. The scraper includes a scraper bucket suspended from a radially extending arm. The bucket is connected to both a digging cable line and a lifting cable line, each of which is in turn connected to a suitable winch. The winches are controlled by clutches and brakes, each of which are optionally activated by interconnected automatic and manual control elements, whereby operation may be selectively changed from automatic to manual at the discretion of the operator.

We claim: 
     
       1. Apparatus for scraping piled-up particulate material against a radial feeder comprising a scraper mounted on a support portion of said feeder, an arm pivotably mounted on said support, a scraper bucket suspended from said arm by a lifting cable line connected to a lifting winch, a digging cable line connected at one end thereof to said bucket and at the other end thereof to a digging winch, motor means for driving said winches, clutch means for connecting said winches with said motor means, brake means for braking said winches, manual control means for directly manually actuating said clutch means and said brake means through linkage means interconnecting said manual control means with said clutch means and said brake means respectively, and power-controlled means for automatically actuating said manual control means, whereby manual and automatic operation are optionally selectable. 
     
     
       2. Apparatus as defined in claim 1, wherein said linkage means includes lever means for actuating said clutch means and pedal-operated rod means for actuating said brake means, and wherein said power-controlled means includes fluid means coupled to said lever means and to said rod means. 
     
     
       3. Apparatus as defined in claim 1, wherein each of said lifting winch and said digging winch are provided with a brake, and wherein said lifting winch brake and said digging winch brake are shiftable to at least two braking levels having different preset braking force values. 
     
     
       4. Apparatus as defined in claim 3, further including damper means provided for at least one of said brakes, said at least one brake including a first braking member adapted to be pressed against a second braking member under the application of an operating force, thereby damping the operating force. 
     
     
       5. Apparatus as defined in claim 4, wherein said damper means comprises a spring arranged to transmit the operating force to the first braking member, said linkage including a force-transmitting rod connected to said spring, and wherein both said manual control means and said power-controlled means are operable against said rod. 
     
     
       6. Apparatus as defined in claim 4, wherein said power-controlled means includes pneumatic means operable against said linkage means for generating the operating force for said brakes, said pneumatic means including a pressurized air feed line, and wherein said damper means is a restrictor in said feed line. 
     
     
       7. Apparatus as defined in claim 1, said radial feeder including a plurality of divider walls extending outwardly therefrom defining a plurality of boxes adapted to contain the particulate material, said scraper bucket being movable along a path to convey the particulate material from the periphery thereof inwardly to a storage area adjacent said feeder and then return to the periphery of the pile of material, and means for sensing various positions of said bucket along said path and for generating control signals in response thereto. 
     
     
       8. Apparatus as defined in claim 7, wherein said sensing means includes means for measuring the angle of rotation of said winches. 
     
     
       9. Apparatus as defined in claim 7, wherein said sensing means are chronometers. 
     
     
       10. Apparatus as defined in claim 7, wherein said arm, together with said scraper bucket carried thereby, is laterally movable over said divider walls to a position over a selected box into which said scraper bucket can be lowered, and an automatically controlled drive for laterally moving said arm. 
     
     
       11. Apparatus as defined in claim 1, further including a motor driven hoist for manual control of the scraper. 
     
     
       12. Apparatus as defined in claim 11, wherein said hoist is mounted with its drive on said support portion of said feeder. 
     
     
       13. Apparatus as defined in claim 1, wherein said motor means for driving said winches includes a protective switch for shutting-off said motor means during overload to prevent damage to said motor means, said protective switch including a time delay element.